In vitro and in vivo MMP gene expression localisation by In Situ-RT-PCR in cell culture and paraffin embedded human breast cancer cell line xenografts

Background Members of the matrix metalloproteinase (MMP) family of proteases are required for the degradation of the basement membrane and extracellular matrix in both normal and pathological conditions. In vitro, MT1-MMP (MMP-14, membrane type-1-MMP) expression is higher in more invasive human breast cancer (HBC) cell lines, whilst in vivo its expression has been associated with the stroma surrounding breast tumours. MMP-1 (interstitial collagenase) has been associated with MDA-MB-231 invasion in vitro, while MMP-3 (stromelysin-1) has been localised around invasive cells of breast tumours in vivo. As MMPs are not stored intracellularly, the ability to localise their expression to their cells of origin is difficult. Methods We utilised the unique in situ-reverse transcription-polymerase chain reaction (IS-RT-PCR) methodology to localise the in vitro and in vivo gene expression of MT1-MMP, MMP-1 and MMP-3 in human breast cancer. In vitro, MMP induction was examined in the MDA-MB-231 and MCF-7 HBC cell lines following exposure to Concanavalin A (Con A). In vivo, we examined their expression in archival paraffin embedded xenografts derived from a range of HBC cell lines of varied invasive and metastatic potential. Mouse xenografts are heterogenous, containing neoplastic human parenchyma with mouse stroma and vasculature and provide a reproducible in vivo model system correlated to the human disease state. Results In vitro, exposure to Con A increased MT1-MMP gene expression in MDA-MB-231 cells and decreased MT1-MMP gene expression in MCF-7 cells. MMP-1 and MMP-3 gene expression remained unchanged in both cell lines. In vivo, stromal cells recruited into each xenograft demonstrated differences in localised levels of MMP gene expression. Specifically, MDA-MB-231, MDA-MB-435 and Hs578T HBC cell lines are able to influence MMP gene expression in the surrounding stroma. Conclusion We have demonstrated the applicability and sensitivity of IS-RT-PCR for the examination of MMP gene expression both in vitro and in vivo. Induction of MMP gene expression in both the epithelial tumour cells and surrounding stromal cells is associated with increased metastatic potential. Our data demonstrate the contribution of the stroma to epithelial MMP gene expression, and highlight the complexity of the role of MMPs in the stromal-epithelial interactions within breast carcinoma.

Stimulation of MMP-11 (stromelysin-3) expression in mouse fibroblasts by cytokines, collagen and co-culture with human breast cancer cell lines

Background Matrix metalloproteinases (MMPs) are central to degradation of the extracellular matrix and basement membrane during both normal and carcinogenic tissue remodeling. MT1-MMP (MMP-14) and stromelysin-3 (MMP-11) are two members of the MMP family of proteolytic enzymes that have been specifically implicated in breast cancer progression. Expressed in stromal fibroblasts adjacent to epithelial tumour cells, the mechanism of MT1-MMP and MMP-11 induction remains unknown. Methods To investigate possible mechanisms of induction, we examined the effects of a number of plausible regulatory agents and treatments that may physiologically influence MMP expression during tumour progression. Thus NIH3T3 and primary mouse embryonic fibroblasts (MEFs) were: a) treated with the cytokines IL-1β, IL-2, IL-6, IL-8 and TGF-β for 3, 6, 12, 24, and 48 hours; b) grown on collagens I, IV and V; c) treated with fibronectin, con-A and matrigel; and d) co-cultured with a range of HBC (human breast cancer) cell lines of varied invasive and metastatic potential. Results Competitive quantitative RT-PCR indicated that MMP-11 expression was stimulated to a level greater than 100%, by 48 hour treatments of IL-1β, IL-2, TGF-β, fibronectin and collagen V. No other substantial changes in expression of MMP-11 or MT1-MMP in either tested fibroblast culture, under any treatment conditions, were observed. Conclusion We have demonstrated significant MMP-11 stimulation in mouse fibroblasts using cytokines, matrix constituents and HBC cell lines, and also some inhibition of MT1-MMP. Our data suggest that the regulation of these genes in the complex stromal-epithelial interactions that occur in human breast carcinoma, is influenced by several mechanisms.

Cultural politics and iconography : an introduction

This collection of papers reflects on the many dimensions of contemporary narratives of iconography in public culture in Australia and Asia. The idea for the volume arose from a series of seminars held at the Centre for Cross-Cultural Research in 2002. The series ‘Iconographies’ was convened by Penny Edwards and centred on research undertaken in the Asia-Pacific, with papers that interrogated national and cultural icons. Just as a biography might examine the makings of a particular personality and her or his shaping of inner and outer worlds, so also iconographic narratives that trace and explore both the evolution and appropriation of particular icons help us mark key moments in the cultural politics of communities, nations and global public spheres. The present volume has two papers (Taylor and Seth) from that series and others on the themes of iconography and iconoclasm that were solicited from a group of interdisciplinary authors working on these themes.

Out of control : Emergent cultural landscapes and political change in urban Vietnam

This paper plots the recent changes in the uses of public space in Hanoi, Vietnam. It is argued that the economic and social changes in contemporary Vietnam have paved the way for a dramatic transformation in the ways in which streets, pavements and markets are experienced and imagined by the populace. The efflorescence of individual mobility, street-trading and public crowding around certain popular events has led to the emergence of a distinct public sphere, one which is not immune from state control and censure but which is a flagrant rebuttal of the state's appeal. The immediate struggles over space herald a new discursive arena for the contest over Vietnamese national imagery as represented in cultural heritage and public space, memorials and state-controlled events which the public are rapidly deserting. The paper concludes by suggesting that the everyday cultural practices that have created a bustling streetlife in urban Vietnam will inevitably provide the vitality and spectacle for the destabilisation of state control in a struggle for meanings in public space.

Stitching at the boundaries : Vietnamese garment industry workers in transnational spaces

This paper explores the interfaces between the transnational politics of labour and the experiences of Vietnamese women garment workers both in Vietnam and as migrants to other countries. As the global industries have come to organise much of the contemporary economic system, so too have they crossed national boundaries in search of cheap labour. At the same time enclaves of migrant disadvantage within the multi-ethnic nation-states of the developed world have also provided workers for the manufacture of clothing. In the case of Australia, these workers are mostly home-based and not in factories. In this paper I explore Vietnamese women's different incorporations into the garment industry in various locations – in Australia, in Vietnam, and in American Samoa. In so doing, I provide an analysis of the links between gender, global power relations and the contradictory space of transnational exchange.

Traffic safety culture : what can we learn from Australia?

-- The role of traffic safety culture in Australia -- A comparison of drink driving (a success story) and speeding (a work in progress) ―Countermeasure approaches ―Community attitudes, perceptions and behaviors -- Lessons from Australia for the further development of the traffic safety culture concept